With the departure of Justice Anthony Kennedy from the U.S. Supreme Court in July of last year, it wasn’t clear exactly who, if anyone, would take his place as the potential swing vote on the court heading in to the court’s most recent term.

The biggest moment in last week’s Democratic presidential debate between California Senator Kamala Harris and former Vice President Joe Biden has brought back to the fore one of the most divisive policies facing education in the 1970s: to desegregate public schools by busing.